A cryogenic transport vessel (or “sample holder” or “holder”) allows a user to transfer samples of organic tissue. In known apparatuses for cryofixation or for cryopreparation, liquid nitrogen or other cryogen, such as liquid helium, is generally used as a coolant and is received in a cooling chamber of the vessel for this purpose. The cryofixation of specimens in the form of biomedical test samples or similarly conditioned physico-chemical test samples is usually carried out by inserting a holder having the specimens into a container of cryogen thereby cooling the specimens to below their glass transition temperature.
During cryotransfer, a specimen in the preferred embodiments herein is maintained at a temperature at or below −160 degrees Celsius to −100 degrees Celsius because the structure of the specimen would change at temperatures above this range, which could render the specimen unusable. In order to transfer the specimen transport vessel with minimal risk to the specimens, the vessel is usually filled with a cryogen so that the cryotransfer of the specimen vessel to another apparatus is conducted with the specimen immersed in the cryogen.
It is common for the cryogen in a vessel to be directly applied to biological specimens. This is usually accomplished by introducing the cryogen into the vessel through apertures, where the cryogen enters into a cavity, and wherein the specimens are in the cavity. Furthermore, once the vessel is removed from the cryogen bath in which it is immersed during shipping, the specimens begin to heat rapidly. A need therefore exists for an improved cryogenic sample holder.